The present invention relates generally to techniques for deicing optical surfaces, such as mirrors, exposed to icy environments outside a vehicle, such as a truck or automobile. External rear-view mirrors are essential to the safety of road vehicles, especially larger vehicles that have no internal rear-view mirrors. In certain weather conditions, ice can form on the mirror surfaces and pose a serious safety hazard. Typically, a driver or passenger in the vehicle cannot conveniently and safely reach the mirror to attempt to scrape away the ice. The use of a resistive heating element behind each mirror provides one possible solution to this problem, but deicing mirrors or windows by this means has the significant drawback that it is slow acting.
Accordingly, it will be appreciated that there is need for an alternative approach to mirror and window deicing, preferably one that acts rapidly to clear an ice layer from a surface. The present invention meets this need.